August 16, 2012

Chocolate Enriched With Flavonol Decreases Blood Pressure

Researchers in Australia recently discovered that flavonol in cocoa may help reduce blood pressure and daily consumption of flavonol-rich chocolate is similar to results found with exercise; the results applied to those with hypertension and normal blood pressure.

In the project, the scientists examined 20 short-term studies done over a 10-year period with 856 adults; they determined that "a statistically significant blood pressure reducing effect of flavonol-rich cocoa products compared with control in short-term trials of two to 18 weeks duration.”

According to TIME magazine, flavonols are compounds taken from cacao beans that can generate nitric acid in the body. Nitric acid helps relax the blood vessel walls and decreases blood pressure.

“Although we don´t yet have evidence for any sustained decrease in blood pressure, the small reduction we saw over the short term might complement other treatment options and might contribute to reducing the risk of cardiovascular disease,” commented Karin Ried, lead researcher of the study from the National Institute of Integrative Medicine, in an article by CBC.

For the study, the researchers scoured online databases for randomized controlled trails. The BBC reports that there was a large range of the amount of cocoa that was consumed; participants ate 3g to 105g a day, depending on the individual. The trials compared people who consumed flavonol-rich cocoa products with people who ate cocoa powder or food compounds with low or no flavonol. The findings indicated that people who consumed cocoa products high in flavonol had a two to three point decline in blood pressure, which is the same amount of change that can be found when a person adjusts diet or participates in regular exercise.

The connection between cocoa and blood pressure was first found among the Kuna Indians, an indigenous group who drank three to four cups of cocoa a day. The people lived on an island off Panama and kept a healthy blood pressure throughout their life time. Those who moved mainland and consumed 10 percent less cocoa demonstrated increase in blood pressure and hypertension as they grew older.

Even though the results show that consumption of chocolate and cocoa high in flavonol can reduce high blood pressure, scientists still cite the importance of exercise and eating right.

“The reduction in blood pressure achieved with cocoa is somewhat comparable to other lifestyle modifications, such as diet and exercise (3-5 mm/Hg reduction), and may serve as complementary treatment option,” Ried told TIME.

In terms of dietary choices, it´s better to eat dark chocolate instead of milk chocolate. Dark chocolate has more cocoa (50 to 80 percent) and more flavonols than milk chocolate. Also, milk chocolate tends to have more sugar and fat. Consumers are also advised to consume chocolate in moderation.

“Smaller dosages may be as effective as larger dosages,” Ried commented in the TIME article. “Larger daily intakes may not be as acceptable and practical.”

Other products are also thought to contain flavonols.

"Beans, apricots, blackberries and apples also contain flavonols and, while containing lower amounts than in cocoa, they won't come with the unhealthy extras found in chocolate,” Victoria Taylor, a member of the British Heart Foundation, mentioned to the BBC.

A drawback of the study was the researchers´ inability to verify if the flavonols were directly responsible for the drop in blood pressure. The compounds have also been connected to the body´s production of nitric oxide, which can help relax the blood vessels and lower blood pressure. The scientists also looked at many different studies with varying amounts of cocoa, which made it difficult for them to identify the ideal amount of cocoa product that can help decrease blood pressure.

"We were unable to identify any randomized, controlled trials that tested the effect of long-term daily ingestion of cocoa products on blood pressure and there were no trials that measured an effect on clinical outcomes related to high blood pressure such as heart attacks or strokes," the researchers wrote in the report.

The findings, published in The Cochrane Library, are of interest as high blood pressure has been considered a major cause of cardiovascular disease, affecting around half of cardiovascular events throughout the globe and 37 percent of cardiovascular-related deaths in the West. The CBC reports that a normal blood pressure is between 120/88 mm Hg and 129/84 mm Hg.

For the future of the study, the researchers hope to have more long-term trials to identify if regular consumption of flavonol-rich cocoa products can allow people to control healthy blood pressure levels and maintain good cardiovascular health. They also wanted to understand if there are any negative side effects related to daily consumption of cocoa products.